Alpha- and beta-adrenergic mediation of changes in metabolism and Na/K exchange in rat brown fat

Double- and triple-barreled ion-sensitive microelectrodes were used to measure changes in extracellular K+ and Na+ concentrations ([K+]o, [Na+]o) in brown fat. Redox states of different respiratory enzymes were measured simultaneously in order to correlate ion movements with metabolic activity. Trains of stimuli applied to the efferent nerves evoked two distinct increases in [K+]o. A first, small, rapid increase occurred within 10 s and accompanied a first, rapid membrane depolarization. A second, slow increase of [K+]o occurred several minutes after stimulation and accompanied a second, slow depolarization. A few seconds after stimulation onset, while the membrane was repolarizing and shifts in redox states indicated increases in lipolysis and respiration, [K+]o decreased. The [K+]o decrease was accompanied by an increase in [Na+]o, and could be partly blocked by ouabain. Phentolamine, an alpha-antagonist that blocks the first depolarization, also blocked the first, rapid [K+]o increase and part of the subsequent decrease. Propranolol, a beta-antagonist, had little effect on the first depolarization and the first increase in [K+]o, but blocked part of the subsequent [K+]o decrease and the second, slow [K+]o increase. The changes in [K+]o were almost completely abolished in the presence of both antagonists. It is concluded that brown adipocytes take up K+ and simultaneously lose Na+ in response to the interaction of noradrenaline with alpha- and beta-receptors, and this indicates a very early stimulation of the Na+ pump

Perfil das mulheres com diagnóstico de malformação fetal grave e/ou incompatível com a vida no HU/UFSC

TCC (graduação) - Universidade Federal de Santa Catarina. Centro de Ciências da Saúde. Enfermagem.Trata-se de um estudo exploratório descritivo, de abordagem qualitativa, com o objetivo de conhecer o perfil das mulheres grávidas com diagnóstico de malformação fetal grave e/ou incompatível com a vida atendidas no HU/UFSC. Este estudo é um recorte do macroprojeto “Mulheres grávidas com diagnóstico de malformação fetal grave e/ou incompatível com a vida do Hospital Universitário da Universidade Federal de Santa Catarina: demanda e itinerário terapêutico”. A pesquisa foi realizada com mulheres gestantes que receberam diagnóstico de malformação fetal grave e/ou incompatível com a vida, que iniciaram acompanhamento pré-natal no ambulatório HU/UFSC, até o parto/nascimento. A coleta de dados foi realizada no período de julho de 2016 a dezembro de 2017, por meio de entrevista semi-estruturada. A análise dos dados foi realizada sob a análise temática de Minayo. Este projeto foi aprovado pelo comitê de ética da Universidade Federal de Santa Catarina sob o parecer número 1.718.023. Em relação à produção de conhecimento sobre o tema, os estudos encontrados abordam as malformações fetais incompatíveis com a vida como ocorrências de etiologia desconhecida na maioria dos casos, que alteram funcional e/ou estruturalmente o desenvolvimento do feto, podendo se apresentar de forma simples ou múltipla. Os estudos apontam que a malformação fetal perpassa todas as classes sociais, faixas etárias, etnias e situações de saúde e no Brasil apresenta-se como a segunda causa de morte do neonato. Apontam que os dados relativos à ocorrência de malformação são subestimados, visto que as mais graves levam ao aborto e outras são percebidas somente ao nascimento. Os resultados desta pesquisa estão organizados em três categorias, a saber: “Aspectos socioeconômicos, culturais e obstétricos”; “Malformações prevalentes no HU/SC/Brasil” e “Itinerário terapêutico”. Conclui-se que ainda são escassos os estudos sobre o tema, sendo necessária maior divulgação das práticas que visem garantir o conhecimento integral da mulher que vive esta situação, bem como sua realidade, potencialidades e dificuldades. Sugere-se que sejam realizadas novas pesquisas que visem desenvolver novas ferramentas e assegurar uma assistência baseada em evidências

Modelo didáctico lúdico clave en el desarrollo de la inteligencia segun Piaget

El modelo Didáctico Lúdico se centra en el interés del niño, de forma apasionante, donde el juego ocupa un espacio primordial que permite dinamizar el proceso de aprendizaje expresándose las emociones ocasionadas por un estimulo que dan lugar a múltiples respuestas. Es más, Piaget establece que "los juegos tendrán un papel fundamental en la asimilación de la realidad según las necesidades del yo; así la acomodación del yo a la realidad (a las servidumbres del entorno social y físico) dan lugar al diálogo con el otro, la interacción, de la cual surge el lenguaje" (Piaget, Jean. Publications /juegos comunicativos, 39k. 1996); este proceso lo podemos denominar 'Motivación Lúdica", paso primordial para introducir al niño hacia la ambigüedad. Ya motivados los niños, se pretende llegar al "Planteamiento" donde Piaget aconseja analizar y sintetizar el problema implicando pensamientos creativos o habilidades refiriéndolo a más de una situación para constituir un nivel de funcionamiento intelectual; además enuncia algunas características que son

Zur Kenntnis tricyclischer Heptalen-Derivate

Es wird über Substituenteneinflüsse auf die Lichtabsorption des Cyclopentadienoheptalens (I) sowie über dessen Reaktionen mit elektrophilen und nucleophilen Agenzien berichtet. In Übereinstimmung mit MO- und LCAO-Berechnungen verhält sich I wie ein Azulen mit in 1.8-Stellung angegliederter Dienbrücke, deren π-Elektronen an der Resonanz des bicyclischen 10π-Elektronensystems teilnehmen. Ausgehend von II konnte das aus drei 7-Ringen und einem 5-Ring aufgebaute tetracyclische System XXXIII gewonnen werden

Multiscale environmental heterogeneity in a large river-floodplain system

River-floodplain systems host very high biodiversity and provide a great variety of ecosystem services due largely to their high environmental heterogeneity, which is strongly dependent on spatial and temporal scales of observation. We aimed to describe the main patterns of environmental variation of the subtropical system of the Middle Paraná River at different scales of analysis using univariate and multivariate statistics. Physical, chemical and biological variables were analyzed during different hydro-sedimentological phases along four consecutive years in 31 aquatic environments. We considered four aquatic habitat types with different degrees of hydrological connectivity and water flow characteristics (major rivers, secondary channels, floodplain lakes permanently connected to the major rivers, and floodplain lakes temporarily connected to the major rivers) from two geomorphologic units with different drainage patterns: anastomosing and meandering. The environmental heterogeneity was mainly associated with the habitat types and relative contributions of lateral tributaries with different water qualities to each unit, in combination with the influence of the hydro-sedimentological regime. The heterogeneity of the system was significantly higher during low water than during high water phases. However, although the extreme flood reduced dissimilarities between habitat types within each geomorphologic unit, it increased differences between major rivers and between units. In conclusion, at different spatial scales, floods may simultaneously have a homogenization effect due to increased hydrological connectivity and a differentiation effect due to enhanced inputs of water from regions with variable geological characteristics and land uses. Finally, geomorphologic units can play a key role in maintaining the environmental heterogeneity during floods of high magnitude, even when land barriers among aquatic environments disappear.Fil: Mayora, Gisela Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Scarabotti, Pablo Augusto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Schneider, Berenice. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Alvarenga Mariani, Patricio Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; ArgentinaFil: Marchese Garello, Mercedes Rosa. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto Nacional de Limnología. Universidad Nacional del Litoral. Instituto Nacional de Limnología; Argentin

Discovery of Fur binding site clusters in Escherichia coli by information theory models

Fur is a DNA binding protein that represses bacterial iron uptake systems. Eleven footprinted Escherichia coli Fur binding sites were used to create an initial information theory model of Fur binding, which was then refined by adding 13 experimentally confirmed sites. When the refined model was scanned across all available footprinted sequences, sequence walkers, which are visual depictions of predicted binding sites, frequently appeared in clusters that fit the footprints (∼83% coverage). This indicated that the model can accurately predict Fur binding. Within the clusters, individual walkers were separated from their neighbors by exactly 3 or 6 bases, consistent with models in which Fur dimers bind on different faces of the DNA helix. When the E. coli genome was scanned, we found 363 unique clusters, which includes all known Fur-repressed genes that are involved in iron metabolism. In contrast, only a few of the known Fur-activated genes have predicted Fur binding sites at their promoters. These observations suggest that Fur is either a direct repressor or an indirect activator. The Pseudomonas aeruginosa and Bacillus subtilis Fur models are highly similar to the E. coli Fur model, suggesting that the Fur–DNA recognition mechanism may be conserved for even distantly related bacteria